The system check framework is a set of static checks for validating Django projects. It detects common problems and provides hints for how to fix them. The framework is extensible so you can easily add your own checks.
For details on how to add your own checks and integrate them with Django’s system checks, see the System check topic guide.
CheckMessage¶The warnings and errors raised by system checks must be instances of
CheckMessage. An instance encapsulates a single reportable error or
warning. It also provides context and hints applicable to the message, and a
unique identifier that is used for filtering purposes.
Constructor arguments are:
levelDEBUG,
INFO, WARNING, ERROR, CRITICAL. If the level is greater or
equal to ERROR, then Django will prevent management commands from
executing. Messages with level lower than ERROR (i.e. warnings) are
reported to the console, but can be silenced.msghintNone can be used.obj__str__ method (on
Python 2 you need to define __unicode__ method). The method is used
while reporting all messages and its result precedes the message.idapplabel.X001, where X is one of the letters
CEWID, indicating the message severity (C for criticals, E for
errors and so). The number can be allocated by the application, but should
be unique within that application.There are subclasses to make creating messages with common levels easier. When
using them you can omit the level argument because it is implied by the
class name.
Django’s system checks are organized using the following tags:
models: Checks governing model, field and manager definitions.signals: Checks on signal declarations and handler registrations.admin: Checks of any admin site declarations.compatibility: Flagging potential problems with version upgrades.security: Checks security related configuration.templates: Checks template related configuration.caches: Checks cache related configuration.urls: Checks URL configuration.Some checks may be registered with multiple tags.
<swappable> is not of the form app_label.app_name.<SETTING> references <model>, which has not been
installed, or is abstract.<app_label>.<model>.id can only be used as a field name if the field also
sets primary_key=True.<field name> from parent model <model>
clashes with the field <field name> from parent model <model>.<field name> from model
<model>.<field name> has column name <column name>
that is used by another field.index_together must be a list or tuple.index_together elements must be lists or tuples.unique_together must be a list or tuple.unique_together elements must be lists or tuples.index_together/unique_together refers to the
non-existent field <field name>.index_together/unique_together refers to a
ManyToManyField <field name>, but ManyToManyFields are not
supported for that option.ordering must be a tuple or list (even if you want to
order by only one field).ordering refers to the non-existent field
<field name>.index_together/unique_together refers to field
<field_name> which is not local to model <model>.<model> contains model fields.<field>.
Maximum length is <maximum length> for database <alias>.<M2M field>. Maximum length is <maximum length> for database
<alias>.<model>.check() class method is currently overridden.ordering and order_with_respect_to cannot be used
together."__".pk is a reserved word that cannot be used as a field
name.choices must be an iterable (e.g., a list or tuple).choices must be an iterable returning (actual value,
human readable name) tuples.db_index must be None, True or False.null=True.AutoFields must set primary_key=True.BooleanFields do not accept null values.CharFields must define a max_length attribute.max_length must be a positive integer.max_length is ignored when used with IntegerField.DecimalFields must define a decimal_places attribute.decimal_places must be a non-negative integer.DecimalFields must define a max_digits attribute.max_digits must be a non-negative integer.max_digits must be greater or equal to decimal_places.FilePathFields must have either allow_files or
allow_folders set to True.GenericIPAddressFields cannot accept blank values if
null values are not allowed, as blank values are stored as nulls.auto_now, auto_now_add, and default
are mutually exclusive. Only one of these options may be present.IPAddressField has been removed except for support in
historical migrations.IPAddressField has been deprecated. Support for it
(except in historical migrations) will be removed in Django 1.9. This check
appeared in Django 1.7 and 1.8.unique is not a valid argument for a FileField.primary_key is not a valid argument for a FileField.ImageField because Pillow is not installed.<handler> was connected to the <signal> signal with
a lazy reference to the <model> sender, which has not been installed.The following checks are performed to warn the user of any potential problems that might occur as a result of a version upgrade.
BooleanField does not have a default value. This
check was removed in Django 1.8 due to false positives.MIDDLEWARE_CLASSES.
django.contrib.sessions.middleware.SessionMiddleware,
django.contrib.auth.middleware.AuthenticationMiddleware, and
django.contrib.messages.middleware.MessageMiddleware were removed from
the defaults. If your project needs these middleware then you should
configure this setting. This check was removed in Django 1.9.TEMPLATE_* settings were deprecated in
Django 1.8 and the TEMPLATES dictionary takes precedence. You must
put the values of the following settings into your defaults TEMPLATES
dict: TEMPLATE_DIRS, ALLOWED_INCLUDE_ROOTS,
TEMPLATE_CONTEXT_PROCESSORS, TEMPLATE_DEBUG,
TEMPLATE_LOADERS, TEMPLATE_STRING_IF_INVALID.Admin checks are all performed as part of the admin tag.
The following checks are performed on any
ModelAdmin (or subclass) that is registered
with the admin site:
raw_id_fields must be a list or tuple.raw_id_fields[n] refers to <field name>,
which is not an attribute of <model>.raw_id_fields[n] must be a ForeignKey or
ManyToManyField.fields must be a list or tuple.fieldsets and fields are specified.fields contains duplicate field(s).fieldsets must be a list or tuple.fieldsets[n] must be a list or tuple.fieldsets[n] must be of length 2.fieldsets[n][1] must be a dictionary.fieldsets[n][1] must contain the key
fields.fieldsets[n][1].fields[n]/fieldsets[n][m] cannot include the
ManyToManyField <field name>, because that field manually specifies a
relationship model.exclude must be a list or tuple.exclude contains duplicate field(s).form must inherit from BaseModelForm.filter_vertical must be a list or tuple.filter_horizontal must be a list or tuple.filter_vertical[n]/filter_vertical[n] refers
to <field name>, which is not an attribute of <model>.filter_vertical[n]/filter_vertical[n] must
be a ManyToManyField.radio_fields must be a dictionary.radio_fields refers to <field name>,
which is not an attribute of <model>.radio_fields refers to <field name>,
which is not a ForeignKey, and does not have a choices definition.radio_fields[<field name>] must be either
admin.HORIZONTAL or admin.VERTICAL.view_on_site must be either a callable or a
boolean value.prepopulated_fields must be a dictionary.prepopulated_fields refers to
<field name>, which is not an attribute of <model>.prepopulated_fields refers to
<field name>, which must not be a DateTimeField, ForeignKey or
ManyToManyField.prepopulated_fields[<field name>] must be a
list or tuple.prepopulated_fields refers to
<field name>, which is not an attribute of <model>.ordering must be a list or tuple.ordering has the random ordering marker
?, but contains other fields as well.ordering refers to <field name>, which
is not an attribute of <model>.readonly_fields must be a list or tuple.readonly_fields[n] is not a callable, an
attribute of <ModelAdmin class>, or an attribute of <model>.ModelAdmin¶The following checks are performed on any
ModelAdmin that is registered
with the admin site:
save_as must be a boolean.save_on_top must be a boolean.inlines must be a list or tuple.<InlineModelAdmin class> must inherit from
BaseModelAdmin.<InlineModelAdmin class> must have a model attribute.<InlineModelAdmin class>.model must be a
Model.list_display must be a list or tuple.list_display[n] refers to <label>,
which is not a callable, an attribute of <ModelAdmin class>, or an
attribute or method on <model>.list_display[n] must not be a
ManyToManyField.list_display_links must be a list, a tuple,
or None.list_display_links[n] refers to <label>,
which is not defined in list_display.list_filter must be a list or tuple.list_filter[n] must inherit from
ListFilter.list_filter[n] must not inherit from
FieldListFilter.list_filter[n][1] must inherit from
FieldListFilter.list_filter[n] refers to <label>,
which does not refer to a Field.list_select_related must be a boolean,
tuple or list.list_per_page must be an integer.list_max_show_all must be an integer.list_editable must be a list or tuple.list_editable[n] refers to <label>,
which is not an attribute of <model>.list_editable[n] refers to <label>,
which is not contained in list_display.list_editable[n] cannot be in both
list_editable and list_display_links.list_editable[n] refers to the first field
in list_display (<label>), which cannot be used unless
list_display_links is set.list_editable[n] refers to <field name>,
which is not editable through the admin.search_fields must be a list or tuple.date_hierarchy refers to <field name>,
which is not an attribute of <model>.date_hierarchy must be a DateField or
DateTimeField.InlineModelAdmin¶The following checks are performed on any
InlineModelAdmin that is registered as an
inline on a ModelAdmin.
<field name>, because it is the
foreign key to the parent model <app_label>.<model>.<model> has no ForeignKey to <parent model>./
<model> has more than one ForeignKey to <parent model>.extra must be an integer.max_num must be an integer.min_num must be an integer.formset must inherit from
BaseModelFormSet.GenericInlineModelAdmin¶The following checks are performed on any
GenericInlineModelAdmin that is
registered as an inline on a ModelAdmin.
'ct_field' references <label>, which is not a field
on <model>.'ct_fk_field' references <label>, which is not a
field on <model>.<model> has no GenericForeignKey.<model> has no GenericForeignKey using content type
field <field name> and object ID field <field name>.REQUIRED_FIELDS must be a list or tuple.USERNAME_FIELD for a custom user
model must not be included in REQUIRED_FIELDS.<field> must be unique because it is named as the
USERNAME_FIELD.<field> is named as the USERNAME_FIELD, but it is not
unique.The following checks are performed when a model contains a
GenericForeignKey or
GenericRelation:
GenericForeignKey object ID references the
non-existent field <field>.GenericForeignKey content type references the
non-existent field <field>.<field> is not a ForeignKey.<field> is not a ForeignKey to
contenttypes.ContentType.The security checks do not make your site secure. They do not audit code, do intrusion detection, or do anything particularly complex. Rather, they help perform an automated, low-hanging-fruit checklist. They help you remember the simple things that improve your site’s security.
Some of these checks may not be appropriate for your particular deployment
configuration. For instance, if you do your HTTP to HTTPS redirection in a load
balancer, it’d be irritating to be constantly warned about not having enabled
SECURE_SSL_REDIRECT. Use SILENCED_SYSTEM_CHECKS to
silence unneeded checks.
The following checks are run if you use the check --deploy option:
django.middleware.security.SecurityMiddleware in your
MIDDLEWARE_CLASSES so the SECURE_HSTS_SECONDS,
SECURE_CONTENT_TYPE_NOSNIFF, SECURE_BROWSER_XSS_FILTER,
and SECURE_SSL_REDIRECT settings will have no effect.django.middleware.clickjacking.XFrameOptionsMiddleware in your
MIDDLEWARE_CLASSES, so your pages will not be served with an
'x-frame-options' header. Unless there is a good reason for your
site to be served in a frame, you should consider enabling this
header to help prevent clickjacking attacks.django.middleware.csrf.CsrfViewMiddleware is not in your
MIDDLEWARE_CLASSES). Enabling the middleware is the safest
approach to ensure you don’t leave any holes.SECURE_HSTS_SECONDS setting. If your entire site is served only
over SSL, you may want to consider setting a value and enabling HTTP
Strict Transport Security. Be sure to read
the documentation first; enabling HSTS carelessly can cause serious,
irreversible problems.SECURE_HSTS_INCLUDE_SUBDOMAINS setting to True. Without this,
your site is potentially vulnerable to attack via an insecure connection to a
subdomain. Only set this to True if you are certain that all subdomains of
your domain should be served exclusively via SSL.SECURE_CONTENT_TYPE_NOSNIFF setting is not
set to True, so your pages will not be served with an
'x-content-type-options: nosniff' header. You should consider enabling
this header to prevent the browser from identifying content types incorrectly.SECURE_BROWSER_XSS_FILTER setting is not
set to True, so your pages will not be served with an
'x-xss-protection: 1; mode=block' header. You should consider enabling
this header to activate the browser’s XSS filtering and help prevent XSS
attacks.SECURE_SSL_REDIRECT setting is not set to
True. Unless your site should be available over both SSL and non-SSL
connections, you may want to either set this setting to True or configure
a load balancer or reverse-proxy server  to redirect all connections to HTTPS.SECRET_KEY has less than 50 characters or
less than 5 unique characters. Please generate a long and random
SECRET_KEY, otherwise many of Django’s security-critical features will be
vulnerable to attack.django.contrib.sessions in your
INSTALLED_APPS but you have not set
SESSION_COOKIE_SECURE to True. Using a secure-only session
cookie makes it more difficult for network traffic sniffers to hijack user
sessions.django.contrib.sessions.middleware.SessionMiddleware in your
MIDDLEWARE_CLASSES, but you have not set
SESSION_COOKIE_SECURE to True. Using a secure-only session
cookie makes it more difficult for network traffic sniffers to hijack user
sessions.SESSION_COOKIE_SECURE is not set to True.
Using a secure-only session cookie makes it more difficult for network traffic
sniffers to hijack user sessions.django.contrib.sessions in your
INSTALLED_APPS, but you have not set
SESSION_COOKIE_HTTPONLY to True. Using an HttpOnly session
cookie makes it more difficult for cross-site scripting attacks to hijack user
sessions.django.contrib.sessions.middleware.SessionMiddleware in your
MIDDLEWARE_CLASSES, but you have not set
SESSION_COOKIE_HTTPONLY to True. Using an HttpOnly session
cookie makes it more difficult for cross-site scripting attacks to hijack user
sessions.SESSION_COOKIE_HTTPONLY is not set to True.
Using an HttpOnly session cookie makes it more difficult for cross-site
scripting attacks to hijack user sessions.CSRF_COOKIE_SECURE is not set to True.
Using a secure-only CSRF cookie makes it more difficult for network traffic
sniffers to steal the CSRF token.CSRF_COOKIE_HTTPONLY is not set to True.
Using an HttpOnly CSRF cookie makes it more difficult for cross-site
scripting attacks to steal the CSRF token.DEBUG set to True in
deployment.django.middleware.clickjacking.XFrameOptionsMiddleware in your
MIDDLEWARE_CLASSES, but X_FRAME_OPTIONS is not set to
'DENY'. The default is 'SAMEORIGIN', but unless there is a good reason
for your site to serve other parts of itself in a frame, you should change
it to 'DENY'.ALLOWED_HOSTS must not be empty in deployment.The following checks are performed on any model using a
CurrentSiteManager:
CurrentSiteManager could not find a field named
<field name>.CurrentSiteManager cannot use <field> as it is not a
ForeignKey or ManyToManyField.If you’re using MySQL, the following checks will be performed:
CharFields to have a
max_length > 255.The following checks verify that your TEMPLATES setting is correctly
configured:
'APP_DIRS': True in your
TEMPLATES but also specify 'loaders' in OPTIONS. Either
remove APP_DIRS or remove the 'loaders' option.The following checks verify that your CACHES setting is correctly
configured:
'default' cache in your
CACHES setting.The following checks are performed on your URL configuration:
<pattern> uses
include() with a regex ending with a
$. Remove the dollar from the regex to avoid problems
including URLs.<pattern> has a regex
beginning with a /. Remove this slash as it is unnecessary.<pattern> has a name
including a :. Remove the colon, to avoid ambiguous namespace
references.May 02, 2016